Audio Terminology And Definitions Dictionary

 

Tape Deck   Machine for playing magnetic tape recordings. Tape decks range from conventional cassette decks, old-fashioned open reel analogue tape recorders, to DCC and DAT tape decks to professional studio tape decks. Most modern studio tape recorders are digital, the conventional storage medium being U-matic tape (a format originally developed as a professional video recording standard).

 

Tetrode   A four electrode tube (valve) based on the triode.

 

Thermal Noise  The very faint background noise added to a signal as electrons pass through semiconductors and cause heat.

 

Three-Beam Laser Transport  A three-beam optical pickup passes light from the laser source through a diffraction grating, resulting in three separate beams. The center beam is used to read data, and it feeds information to keep the beam focused. The two other beams are used for tracking. (See also: single-beam laser transport.)

 

THX  Both an organization and a set of certification standards, THX was originally established by Lucasfilm Ltd., but it has since been spun off as a separate organization. The original idea behind THX was to establish a protocol to ensure that what you hear in your home theater comes as close as possible to what the soundtrack engineer originally intended. THX technologies work in cooperation with surround sound "pipelines" such as Dolby Digital or DTS, not in competition with them. Equipment bearing the THX logo must meet certain minimum performance standards. See the chapter on THX for further details.

 

TIFF (Tag Image File Format)     A flexible container format for digital still images, TIFF is commonly used in desktop publishing. TIFF images can incorporate various forms of compression (e.g., JPEG), or they can be uncompressed.

 

Tonmeister  Literally tone master. The term used by Deutsche Grammophon to describe the function performed by the professional recording engineer. The role requires microphone positioning and choice, operation of tape recorders for all takes during a recording session. Ultimately the Tonmeister or recording engineer  is responsible for the sound quality of the master tape. 

 

Toroidal Transformer   A donut-shaped transformer that provides higher efficiency and lower stray magnetic fields for its size when compared to an equivalently sized standard iron-core transformer.

 

TosLink  TOSlink is a fiber-optic connection originally developed by Toshiba that is used for transferring digital audio signals (such as PCM, Dolby Digital, and DTS) from a source device (CD or DVD player) to an A/V receiver or preamp/processor.

 

Total Harmonic Distortion (THD)     Expressed as a percentage of an original audio signal, THD is the total of all harmonics not present in the original signal.

 

Tracking  The ability of a cartridge to track the record microgroove. A down force or tracking force is applied by a counterweight on the end of the tonearm to which the cartridge is attached. An appropriate side force (bias) is also applied to ensure the cartridge is not dragged towards the center of the disc. Typical downforce values of around 1.8 to 2.0gm are used today, depending on the mass of the arm and cartridge and the compliance of the cartridge suspension system. A high mass cartridge (10gm or more) and high mass tonearm (15gm or more Effective mass), low compliance (10 cu or less) combination may require a down force in excess of 2.0gm.

 

Transcoding Transcoding is the process of converting a media file from one file format to another to ensure that the content of the original file will play on a system originally developed to handle a non-compatible file format. Transcoding is usually accomplished with specific computer programs developed for the purpose. Some programs convert the files and save them to be played later. Other programs or smartphone apps, such as Air Video, "live convert" the files for immediate streaming.

 

Transducer  Any device that converts one form of energy into another. A solar panel, for example, is a transducer because it converts sunlight into electricity. Almost all loudspeakers are actually "double transducers" in that they first convert electrical energy (from an amplifier) into mechanical energy (a piston moving back and forth), and then they take that mechanical energy and convert it into acoustical energy (sound waves) that we can hear. Both types of energy conversion (electrical to mechanical, and mechanical to acoustical) are very important design factors in any loudspeaker.

 

Transient A rapid, short-duration change of an audio signal that tests, naturally enough, something called "transient response," or the ability of a component (usually a speaker) to respond to a sonic event as quickly as possible and then return to a state of rest when the signal disappears. The so-called "rim shot" produced by a drumstick on the edge of a drum is an excellent example of a transient.

 

Treble     The upper-level or highest band of audio frequencies, running from about 3000 Hertz to 20,000 Hertz. (See also: bass, midrange, and octave.)

 

Triode  The first electronic amplification device. Invented in 1907 by Lee de Forest who called it the audion, the triode is a diode with an extra perforated electrode, the grid, whose function is to vary the amount of current flowing from anode to cathode.

 

Transient   A sudden sound.

 

Transistor   There are numerous types of transistor, all designed to amplify an electrical signal. The most common form used today is the bipolar transistor. There are also J-FETS, MOSFETs, HEXFETs and many other generic types with particular applications.

 

Transmission Line   A type of box loudspeaker in which a folded chamber leading from the rear of the bass unit exits in the form of a vent. The aim of a transmission line is to make the chamber sufficiently long and filled with sufficient material such as acoustic fibre, to prevent rear radiated sound exiting the cabinet. Ideally all the sound will have been converted to heat by the acoustic fibre.

 

Tuner  An audio or video component designed to receive radio or television broadcasts.

 

Tweeter   A driver designed to reproduce the high-frequency (treble) range of the audio spectrum. (See also: driver, midrange driver, and woofer.)

 

Two-Way, Three-Way, etc.  Refers to a speaker system in which different drivers are tasked with reproducing defined frequency ranges. A two-way speaker, for example, usually includes a woofer and a tweeter. A three-way speaker adds a midrange driver to the driver complement.